1. Field of the Invention
The present invention relates generally to ink cartridges for high speed computer driven printers such as ink-jet printers and plotters and, more particularly, to reservoir systems for ink cartridges having capabilities for media marking in multi-color applications.
2. Description of the Related Art
In the field of ink-jet printing, ink (or "colorant") may be kept in a reservoir and maintained under a sub-atmospheric (or "negative") pressure, so that ink will not leak, also referred to in the art as "drool," from the printhead attached to the reservoir. Such a printer cartridge is described in U.S. patent application Ser. No. 995,851 (Kaplinsky) referenced and incorporated above.
Various types of ink reservoirs have been used, including both disposable and refillable ink reservoir cartridges which are mounted on a moveable printer carriage, and remote, or "off-board," ink reservoirs from which ink is drawn to the printhead through a tubing system.
In the on-board, disposable or refillable, ink reservoir cartridges of the prior art, a polymer foam is ordinarily provided in the ink reservoir so that capillary action of the foam will prevent ink from drooling inappropriately from the printhead. Polymeric foams of the type typically used for this purpose are non-biodegradable and thus cause environmental problems whenever an expended cartridge is discarded. In addition, the use of industrial foam in the ink reservoir restricts the operating pressure range of the ink cartridge and can leave a chemical residue which is incompatible or reacts adversely with printer ink.
Similarly, the relatively long tubing used to convey ink from an off-board pressure reservoir to a printhead does not lend itself well for different printing pressure ranges.
Therefore, there is a need for an on-board ink reservoir system for printers and plotters that does not rely upon foam-based ink retention mechanisms.